Imperial City is not Faction Locked

The craziest thing happened yesterday. Me and my guildies were playing in IC on our EPs, when SUDDENLY our guildmate who has been locked to AD for the last few campaigns came on his EP and joined our group!

We had a ton of fun together and enjoyed a great evening which is completely unacceptable. Please faction lock IC instantly so we can't have fun with our friends even during the event.